Telephone system.



W. W. DEAN.

TELEPHONE SYSTEM.

APPLICATION FILED JUNE 29, 1903.

Patented Nov. 10, 1908.

Figure 1 a diagram of a telephone s Gi i \JlLLlA M W. DEAN, OF CEEC COMPANY, OF CHICAGO, ILLI no. eoas rz.

NESTED Fiiilr iTiES Pailfihll @F AGO, ILLINOIS, ASSIGNOR 'lO KELLOGG NOIS, A CORPORATlON 01* ILLINOIS.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Fatented Nov. 10,

Application filed Tune 29, 1903. Serial No. 163,611.

To all whom it may concern:

Be it known that I, W 1LLL\1\[ ll. DEAN, a citizen of the United States of America, and resident of Chicago, county of Cook, and

State of Ilinois have invented a new and useful Improvement in Telephone Systems, ot which the following 15 a spec fication.

My invention telephone systems relates to improvements in and apparatus and has for its object the provision ot' ineans whereby a reduction in the amount ofthe apparatus required for either the telephone line or the cord circuit or ordinary system in my invention I arrange in association both over that of the is secured.

with the telephone line a single magnetic device preferably in the form of a relay, which isprovidcd with two magnet coils, one serving when operated singly to close tho'relay circuit and the other coil serving when actuated t not and cti'ect. a

o overpower the other magchange in the CllCllli? or apparatus controlled by the said device. I may use such a device in connection with the telephone line c line and cut-oil Lioned serving the line signal when sutlicipntly energized first mentioned ircuit in place of the usual relays, the first coil menwhen energized to operate and the other coil serving to overpower the magnet'and eilace the said s nal. This device may also be conven Eently used in c onnection with the supervisory system oi the cord circuit in which the first magnet coil is connected with the cord strand through which circuit is first established when connection is made with an idle telephone nal is operated,

line. whereby the supervisory sigand the second magnet bein in the path of current over the telephone line and therefore under the control of. the HllbSClll'Xi' and serving when the telephone is in use to overpower the first magnet and rot ire the said signal. It is also obvious that the two devices are particularly adapted tor use in the same system and with a consequent reduction in both the line circuit' and cord circuit apparatus.

My invention is illustrated in the accompanying drawing in which teni embodying my improvements;

is a sectionalview through the two magnet coils, and Fig. 3 is a front view of'the de vice.

in Fig. 1, l1 an d L indicate two subscribers n t/ill SWITCLEBOA lti) it SUPPLY lines extending in two limbs .2 and 3 from their re oilice. Lit ti iective substations to the central substations they zre provided with an ordinary hell #1 and a condenser 5 111 a permanent bridge of the line and with a transmitter (3 and receiver bridge whose normal discontinuity is .maintained by the switcliliook 8.

This apparatus is 111- tended to typify any usual or desired common battery outfit.

At the central office the line is provided with answering and multiple jacks J,

and J 3 having their two main line contacts permanently connected with the corresponding line conductors 2 and 3. The line Sig naling device consists of a magnet coil 9 of high resistance included in. the extension of the line limb 2 over conductor 1().to the live pole of the central and common battery B, and a low resistance magnet coil 11 included in the sleeve conductor 3 of the telephone line.' A suitable armature lever is pivoted between these magnet coils and is normally prevented from engaging the ground con tact 13 by 'a weight 14, or equivalent device,

and which armature is connected with the conductor 15 through the line.

leading to the battery wire line signal S ofthe telephone \Vhen the magnet 9 is energized therefore the signal S has its local circuit closed at the contact 13, and energized said from said contact. 1?) and the circuit signal is opened.

when the magnet. 11 is armature 1'3 is drawn away of the The cord circuit includes the answering and calling plugs l and 1 respectively, having their tip contacts connected together by the strands t and t and theinterposed condenser 0, while their sleeve contacts are joined by posed condenser 0 The live pole contacts 5 and s and the interof the battery is connected by means of conductorlG with one coil 17, corresponding in this magnet 9 of the line signaling device,

terminal of the magnet device to the and nal with the tip strand t of the The supervisory by means of conductor 20.

circuit signal S has its local circuit completed from live pole ofthe battery armature 21 'of'said magnets and the through the branch I cuit controlled by a the magnet 17 is connected by conductors 23V and 24 between the live pole of a central common battery 13 and the sleeve strand 8 of the cord circuit, while the magnet 19 is connected by conductor 25 from the ground pole of the battery B to the strand t of the cord circuit. The operators head telephone 26, the secondary of her induction coil 27 and a suitable condenser c are adapted to be bridged across the calling end of the cord circuit by means of any suitable listening key, preferably one in which the operation of a single lever simultaneously connects the operators bridge with the two strands t and s of the cord circuit. Asuitable calling generator 28 is adapted to be connected between 'ground and the tip strand t of the cord circuit by means ofthe tip spring 29 of the ringing taneously connecting the forward portion of the sleeve strand 8 of the cord circuit with the conductor 30 including a resistance v 31 and the battery lead 10 extending to the through coil live pole of the battery B which latter battely is common preferably to all of the cord circuits and a large number of telephone lines.

In the particular system shown the two coils 9 and 11 of the line signaling device are placed in series in the path of current over the telephone line so-that when the subscriber takes up his receiver, current will .fiow from the battery B over conductor 10,

9 of the device, over tip conductor 2 through the substation devices and thence back conductor 3 and through the magnet coil 11.

The coil 9 is of sufficiently high resistance and the coil 11 of sufliciently low resistance so that the magnet 9 is now actuated and serves to close the local circuit of the line signal S through its forward contact 13.

These coils may have various resistances to the telephone line, whici permi they are used, but in the adapt them to the particular system in which system shown it is found desirable tomake the coil 9 of 1.000 ohms resistance, and the coil 11'of 100 ohms resistance. The line coil 9 is thus made scnsitive' to the calling current and readily operates to cause the'operation of said signal.

Upon observing the signal the operator inserts the answering pin P in tbe ack J of 's current to flow from the live pole of said battery B over conductor 16, coil 1.7 of the. supervisory device, conductor 18, sleeve 's't cord circuit, through the sleeve conductor of key, the sleeve spring simulto the central station over line rand s of the the jacks of the line and the coil 11 of the line signaling device to ground. This cir-. cuit is directly in shunt of the line with its high resistance so that the coil 11 receives sufiicient current to operate the same, causing it to attract its arn'iature thus overpowering the coil 9 and opening the local circuit of the line signal S which is accordingly effaced. Owing to the fact that thesubscribers telephone is off its hook current will now also circulate over the metallic telephone line and through the cord strand t and conductor 20 including the winding 19 of said supervisory device. The resistance of each'of the coils 17 and 19 may be 100 ohms. These coils and the weight 14-, or equivalent means, are so adjusted that the coil 19 is energized sufficiently under these condi ions to attract its armature and overpower the magnet 17 and prevent the closing of the local circuit of the signal S which accordingly remains inert. v

Connecting her instrinnentwith the cord circuit the operator receives the order from the calling subscriber and proceeds to test the idle or busy condition of the line. It idle the test rings of the jacks of the line are connected to ground through the coil 11 of the line signaling device, and since the-tip of the testing plug is likewise normally grounded no flow of current results when the line is tested and no click is received. Should the line be connected for conversation, however, the test rings are connected with the live pole oi either the battery B or B through the sleeve strand oi the inserted cord and the ap )lication of the ground'ed'tip of the testing plug thereto results in a flow of current over the strand 6 oi the testing cordand a change of potential at the terminals of jhe operators bridge which causes a surge of current through the operators instrument and PI'OtlllCQS a click. The operator is thus informed that the line is busy.

Assuming that the line is found idle, the 1 calling plug 1" is inserted in one of them'ultiple JZl'CliS of the callingline at the oper- ,ators section and the ringing key operated.

The ringing current finds a path out over the tip side of the tcleplunie line, through the calling device at the substation and back to the central ollice and through the forward portion oi the sleeve strand s conductor 30,

resistance 31, lead 10 and battery B to ground. The flow oi steady current over the sleeve conductor of the cord circuit tends to maintain the magnet 11 actuated but even it the ringing current asses through the cut-off magnet 11 no great harm results.

After the subscriber has been called but before his response current is flowing over the sleeve conductor 8 of the cord circuit and through the winding 11. of the line signaling device 1hr ground. The current through the coil 17 .of the supervisory deyet responded. At the same time the cut-off ,sults in opening the local circuit of the superand 19, are located, and acting upon the op the rear of the magnet bar and are suitably the armature 21 by means of which the see,

vice is suiiicient to close the local circuit of the supervisory signal S which is lighted to indicate that the called subscriber has not magnet 11 of the called line is energized so that the line signal belonging to that line does not operate. Upon the response of the called subscriber current is allowed to flow over the tip strand t and magnet 19 of the supervisory signaling device. This results, as before explained, lnoverpowering the effeet of magnet 17 on the armature which revisory signal S to retire the same, thus indicating tothe operator that the subscriber has responded.

. During conversation the batteries B and B are sending current out over the telephone lines for talking purposes and for the operation of the various magnet coils. At the termination of the conversation when the subscribers return the recivers to the hooks current is cut oil from the'coils 1 of the supervisory signaling devices with the result that the coils '17 immediately close the local circuits of said signals which are lighted to indicate the fact of the termination of the conversation to the operator, and the opcrator accordingly takes down the connection and restores all parts to normal.

It is obvious that my invention is not limited to the exact construction shown and that it may be embodied in various forms and the coils maybe varied in their electrical and other dimensions to suit the requirements of the particular system in which it is desired to use the same.

In Figs. 2 and 3 I show one practical embodiment for the signaling device. In these figures 35 represents a casing or shell of cast iron or other magnetic material, in which a pair of magnet coils, for example the coils 17 posite ends ofthe armature 21 pivoted upon the pin 36, supported at its ends in the studs 37 secured to the front. face ol" the bar 35 in which said coils are located. The up )er end of the armature 21 carries an adjusta le contact 38 which is adapted to engage the stationary contact 39 mounted upon the front end of the spool of the upper magnet coil 17 and connected by the terminal 40 through therear oi": the magnet bar. The other terminals 41 and 42 are likewise projected from connected with the ends of the coils 17 and 1i). An ad ustable weight 141 is carried by proper adjustment ot'the armature for the particular system in-which the device is to be used, may be secured.

Having described my invention, what I claim, is:

'1. In a telephone system, the combination with a telephone circuit, of a common source of current at the central oliice, an eleetromagnetic mechanism including two magnet coils both operable over circuits including portions of the talking circuit, one of said coils being energized to attract its armature and the other coil being energized at another time to attract its armature, the latter armature being operated against the force of said first mentioned coil, both of said coils receiv ing current simultaneously from said common source, and telephone apparatus controlled by said armatures, substantially as described" 2. In a telephone system, the combinatio'n with a telephone circuit, of a common source of current at the central oilice an'electromagnetic mechanism including two magnet cores both energized over circuits including portions of the talking circuit, a signal controlled by the magnetism in said' cores, one of said cores being magnetized at one time to affect the said signal and the other core being magnetized at another time to affect said signal, said second core operating in affecting said signal against the magnetic force of said first core, both of said cores being energized simultaneously by current from said common source, substantially as described.

3. In a telephone system, the combination with a telephone circuit, of a connnon source of current at the central oliice, an electromagnetic mechanism including a pair of magnet coils, a signal controlled by said coils, one of said coils serving at one stage of the operation to be energized to cause said signal to be exposed, and the other coil serving at another stage of the operation to be energized and cause said signal to bc eilaced, said second mentioned coil operating in etl'acing said signal against the force of said first mentioned coil without annulling themagnelic force: of said first coil, both of said coils re ceiving current simultaneously from saidi common source over a portion of the talking circuit, substantially as described.

4. In a telephone system, the combination with a telephone circuit, of a common source of current at the central ollicc, an electromagnetic mechanism including two magnet coils both operable over circuits including portions of the talking circuit, a signal having its circuit controlled by said coils, the o ieration of one of said magnet coils serving to close the circuit of said signal thus causing the signal to be exposed and the operation of the other magnet ooihserving to open the circuit of said signal whereby said signal is eilaced, said second mentioned coil operat ing to overpower the magnetic pull of t e first coil without annulling it, both ct lid coils receiving current simultaneously 110111 said common source, substantially as described. 5. in a telephone system, the coinl'nnation with a telephone eircuit, of a common source of current at the central office, a signal adapted to be displayed from said source, an electro-magnetic mechanism including a pair of coils both operable over circuits including portions of the talliing circuit and acting upon a single armature, one of said coils serving to operate said armature in one direction and the other coil serving to move said armature in the. reverse direction, to control the connections of said source with said signal, said second mentioned coil operating in moving'said armature against the power of said first mentioned coil, both of said coils being adapted to receive current sinniltaneously from said common source, substantially as described.

6. In a telephone system, the combination with a telephone line, of a cord circuit for making connection with the line for cenversation, a supervisory signal associated with the cord circuit, a common source of current at the central office for energizing the telephonic apparatus, and an electro-magnetic mechanism having two coils and a single armature controlled thereby for'controlling the circuit of said signal, both of said coils being adapted to receive current from said common source, one of said coils being adapted to cause the operation of said signal by attracting said armature when a connection is made with a line for conversation, the other of said coils being adapted to overpower and attract said armature away from said first mentioned coil when the subscribers telephone is removed from its hook, whereby said signal is eitaced, substantially as described. I

7. In a telephone system, the combination with a telephone line, of a cord circuit for. making connect on with the hne for conver-- sation, a signal forsupervising said connection, a common source of current ht the central oflice for energizing telephonic apparatus, and an electromagnetic mechanism having two coils for controlling the circuit of said signal, both of said coils being adapted to receive current from said source, one of said coils being adapted to cause the operation of said si nal when a connection is made with a line Ior conversation. over a path local to the central ofiice, the other of saidcoils being adapted to overpower said first mentioned coil over a path including the substation apparatus when the subscribers telephone is removed from its hook, whereby said signal is eiiaced, substantially as described.

8. In a telephone system, the combination.

with a telephone line,of a cord circuit for making connection therewlth for conversation, a suitablesignal for supervising sald connection, a-common source of current 10- cated at the central office and an electro-magnet-ic mechanism having two coils for controlling said signal, both of said coils being adapted to receive current-from said source, one'of said coils being adapted to cause the operation of said signal by the attraction of an armature-when a connection is made with a line for conversation, said coil being under the central ollice, an electro-magnetic mech-, anlsm having two magnet colls for controlling said signal,,s aid coils being adapted to receive current from said source and having different magnetic circuits, a single pair of contacts for said mechanism, one of said coils being adapted to cause the operation of said signal when a connection is made with a line 'for conversation, the other of sa-id coils being adapted to overpower said first mentioned coil when the subscribers telephone is removedtromits'hook, whereby said signal is efi'a-ced, substantially as described.

10. In a telephone system, the combination with a telephone line, of a cord circuit for making connection therewith for conversation, a supervisory signal associated with the cord circuit, an electro-maqnetic mechanism for controlling said signal, said mechanism having two magnet coils and two magnetic circuits, one of said coils bein adapted to cause the operation of said signai the other of said coils being ada ted to overpower said first coil to efiace sai signal, sub- WILLIAM W. DEAN.

l Vitnesses:

ROBERT LEWIS AMns, EVA A. GAnLooK. 

